A plasma source is a device which transforms a feed gas or gases into a quasi-neutral, non-thermal plasma, by means of an externally applied electric/electromagnetic field. In the process of transforming gas into plasma, the gas particles can be excited, ionized, and/or dissociated. All of these aforementioned transformation processes are sensitive to: pressure, density, and residence time (the time spent in the applied electric field). The semiconductor and any thin film application may benefit from improved plasma source devices and methods.